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(No Model.)

G. W. KING. PNEUMATIO RAILWAY SYSTEM.

Patented May 6, v1890.

/N VEN TOR Geary@ 2li/Zi W/ TN E SSE S A TTORNE YS UNITED STATES PATENT OFFICE.

GEORGE KING, OF VASHINGTON, DISTRICT OF COLUMBIA.

PN EU MATlC-RAILWAY SYSTEM.

SPECIFICATION forming part of Letters Patent No. 427,330, dated May 6, 1890.

I Application ined february 15,1890. serai No. 340,644. (No model To @ZZ whom it may concern:

Be it known that I, GEORGE W. KING, residing in Washington, in the District of Columbia, have invented certain new and useful Improvements in Pneumatic Railway Systems, of which the following is a specilication.

My invention relates to pneumatic railways; and it has for its object to provide simple and eiiicient devices between the car and the air-tube whereby a continuous airpressure will be supplied to the motor on the car-body and whereby any undue friction and air-pressure on the cut-off valves is avoided during the time in which they are spread apart by the connecting-tube.

To this end my invention consists in the peculiar construction and arrangement of parts, all of which will hereinafter be fully shown, described, and claimed, reference being had to the accompanying drawings, in which* Figure lis a longitudinal section of a portion of the air-tube or conduit with my improvements applied. Fig. 2 is a cross-section thereof on the line 2 2,Fig. l;and Figs. 3 and 4 are similar views on the lines 3 3 and 4 4 of Fig. l, respectively.

In the drawings, A indicates the compressedair tube, which is in the nature of an underground conduit adapted to be buried along the track midway between the rails, provided at its upper face (which is arranged flush with the street-surface) with a continuous slot a.

B B denote flap-valves riveted to theinner edges of the slot, arranged to fold' one B against the other B, in a manner most clearly shown in Fig. 4 of the drawings. The flaps B B are formed in any suitable manner, so as to present continuous or uninterrupted cut-off valves the entire length of the slot a.

C denotes the piston formed of a tube of a slightly-less diameter than the air-tube A, upon vthe outer edges of which are secured the packing-rings c c, as shown, which serve to make a close joint between the tubes A and C. The upper face of the piston C has a central depression C', of a shape substantially as shown in the drawings, said depression serving as a convenient recess for the ends of the valves B B to iit into as they are depressed in the manner presently explained.

D denotes the hollow connectingshank, which is rigidly secured at its lower end to the piston C centrally of the recess C', its upper end adapted to be connected with any suitably-constructed motor on the car-body, (not shown,) such connection, however, in practice being preferably made exible to admit of lateral movement of said shank, owing to the unevenness of the road-bed, &c., The shank D is formed elliptical in horizontal section, (see Fig. 3,) the ends CZ d serving as openers or spreaders as they pass along in the slot a of the tube, and serves to make a continued communication between the tube Aand the motor.

To form a means whereby the flaps may be gradually opened and closed as the shank passes along,I provide the lower longitudinal faces with horizontally-disposed cams d d2, having curved under faces d10 cl20,one of such cams d20 being longer at each end than the opposite cam d10, as shown.

Heretofore in pneumatic-railway systems, so far as I know, a series of flap-valves have been employed to close the slot-opening in the conduit, the pressure of the compressed air serving to always keep them in a closed position; but no means have been as yet employed whereby such pressure on the said valves will be released as the connecting pipe or shank operates to spread them apart. It is obvious that by the aforesaid construction the said flap-valves will always bear against the shank or air connecting-tube with great friction, and that great pressure must necessarily be eX- erted to open them, thereby subjecting them to undue strain and soon wearing them out, thereby causing a leakage of the air-cylinder and rendering the system inoperative. To

.overcome these serious and vital objections,

I provide means whereby as the air connecting-shank D passes along the tube A communication will be had between the atmospheric air and the air in the pocket or chamber formed between the piston and the tube A, which serves to press the valves against the slot, whereby so much of the valves as is necessary to be spread apart will. be relieved of .TOO

such air-pressure, thereby reducing the frictional wear on the valves to a minimum. To this end I provide the shank D with short vertical air-channels D, the upper ends D2 of vwhich open out above the conduit, while the lower ends D3 open into the space F between the cylinders A and C at a point below the flap valves when in their lowermost opened position. It will thus be seen that should any compressed air be in the pocket formed between the two cylinders A and O it will escape through the channels D, thereby relieving the pressure against the flaps, as stated.

By reference to Fig. 4 of the drawings it will be seen that I arrange the' flap B to lap the upper flap B, so as to form a tight valvejoint and to provide for opening the lower flap before the upper, and also, to permit the lupper to close before the lower iiap, I make the cams d cl2 of different lengths, as before stated, the cam d2 serving to engage the flap B slightly in advance of the cam d', engaging the flap B, and hold said iiap Bl from closing until the flap B closes in advance.

Any suitable means for securing the iiapvalves to the conduit may be employed, as also any suitable means for Xedly connecting the tube-shank D to the piston.

From the foregoing description, taken in connection with the drawings, the advantages of my improvement will appear. It will readily be seen that the construction is such as to always render a connection between the compressed-air tube and the motor, at the same time providing a simple, cheap, complete, and practical pneumaticrailway system.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s-

1. In a pneumatic-railway system, the combination of a slotted tube, the valves for normally closing said slot, the piston C, a pocket or chamber formed between the piston and tube, and the tube-shank D, provided with lateral proj ections adapted to force said valves conduit-wall, a tubular shank communicating with the piston at its lower end, its upper end adapted to communicate with a motor on the car, an air channel or channels formed in the said shank, opening at the upper end into the atmospheric air above the conduit, and the pocket between the piston and the conduit, substantially as and for the purpose specified.

3. In a pneumatic-railway system, the combination of the compressed-air tube provided with a continuous slot in its upper side, atubular piston adapted to travel in said slot, having a central depression on its upper face, a tubular shank connected to said depressed portion to communicate with the tubular piston and projected above the slot, and the continuous nap-valves arranged to normally close the slot a and to be forced down by the said shank into the depressed portion of the tubular piston as the shank and piston are moved forward, substantially as and for the purpose described.

4. In a pneumatic-railway system, the combination, with the'compressed-air tube A, provided with a continuous slot a, and the flapvalves B B', arranged to overlap said slot, of the tubular piston C, provided with a central depression, and the tubular shank D, connected with the piston C centrally of the depression, said shank formedessentially elliptical in horizontal cross-section, substantially as and for the purpose described.

5. In a pneumatic-railway system, the combination, with the cylinder A, provided with a continuous slot a, and the Hap-valves for normally closing said slot, of the tubular pist0n C, provided with a central depression, the packing-rings c c at the outer ends thereof, and the shank-tube D, connected to the tubular piston, said shank formed essentially elliptical in horizontal section, provided with curved projections d cl2, adapted to engage the flaps and hold them in open position, substantially as and for the purpose described.

6. The combination, with the air-tube A, provided with a continuous slot a, in its upper side, and the Hap-valves B B', secured to normally close said slot, said valves arranged one B to overlap the other B, of the tubular piston C, provided with a central depression, and the hollow elongated shank D, provided with curved cams or projections d d2, one of said cams d2 being longer than the other d', said cams adapted to engage the valves B B one in advance of the other and to allow said valves to close one in advance of the other,.

substantially as and for the purpose described.

7. The combination, with the air-tube A, provided with a longitudinal slot a, and the ap- IOO IIO

valves heldto normally close said slot, of the tubular piston C, having a central depression C', the elongated hollow shank D, connected to and communicating with the tubular piston, and air-channels D', formed in said shank,

said channels communicating with the at- Giro. wf KING.

Vitnesses:

SoLoN C. KEMON, FRED G. DIETERICH. 

